大鼠下丘脑室旁核在高张NaCl溶液抗失血性低血压中的作用

用大鼠股动脉放血致矢血性低血压的实验模型，以观察下丘脑室旁核（ＰＶＨ）在注射高张ＮａＣｌ溶液引起的升压反应中的作用。结果表明：（１）ＰＶＨ电损毁或假损毁后，小剂量高张ＮａＣｌ溶液静脉注射引起动脉血压（ＡＰ）有意义地迅速回升，但５ｍｉｎ后开始下降，损毁组下降速度快，３５ｍｉｎ后，平均动脉压（ＭＡＰ）回降至注射前水平。组间比较，２０ｍｉｎ后，损毁组ＭＡＰ回升值明显低于假损毁组（Ｐ＜０．０５）。（２）失血后５ｍｉｎ内假损毁组ＨＲ有意义地减慢；明显低于损毁组（Ｐ＜０．０５）。（３）ＰＶＨ微量注射高张ＮａＣｌ溶液（ＨＳ组）后，ＡＰ有意义地回升。对照组（ＮＳ组）则无明显回升。组间比较，ＨＳ组ＡＰ值显著高于ＮＳ组。结果提示：ＰＶＨ参与高张ＮａＣｌ溶液抗矢血性低血压时的升压反应，在血压恢复后的维持阶段起重要作用。

THE ROLE OF PARAVENTRICULAR NUCLEUS OF HYPOTHALAMUS IN ANTAGONIZING HEMORRHAGIC HYPOTENSION WITH HYPERTONIC SODIUM CHLORIDE SOLUTION IN RAT

The role of paraventricular nucleus of hypothalamus(PVH) in pressor response induced by hypertonic sodium chloride solution in hemorrhagic hypotension was observed in rat. It was found that in the rats with electrolytic lesion or sham lesion of PVH, under the state of hemorrhagic hypotension, intravenous infusion of 7.5% NaCl solution may lead to the arterial blood pressure(AP) significantly to recover immediately. However, 5 min after infusion, AP began to reduce. In PVH-lesioned rats,it reduced fast,the mean arterial blood pressure(MAP) returned to the pre-infusion levels within 35 min. Twenty min after infusion, the MAP was significantly lower ih PVH-lesioned group than in sham-lesioned group(P<0.05). Heart rate became slow significantly within 5 min after bleeding in sham-lesioned group. It was remarkbly lower than that in PVH-lesioned group, P<0. 05. Microinjection of hypertonic sodium chloride solution into PVH, AP recovered significantly. And microinjection of normal saline into PVH, AP did not recover.These results indicate that PVH participate in the pressor response to injection of hypertonic sodium chloride solution in hemorrhagic hypotension rats and may play important role in the maintaining stage AP.